Acute respiratory distress syndrome and severe pneumonitis after atezolizumab plus bevacizumab for hepatocellular carcinoma treatment: A case report

BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and has a high mortality. However, the treatment options for advanced HCC are limited to tyrosine kinase inhibitors, such as sorafenib and lenvatinib. Since previous regimens have an insufficient efficacy, the combination therapy of atezolizumab and bevacizumab (Ate/Bev) has been investigated, which showed an improvement in progression-free and overall survival. However, the adverse events of this combination therapy in advanced HCC have not been established. Herein, we report a novel case of an unresectable HCC and acute respiratory distress syndrome (ARDS) after a combination therapy of Ate/Bev. CASE SUMMARY: An 82-year-old male visited our outpatient clinic for an incidentally detected liver mass. Liver magnetic resonance imaging and enhanced chest computed tomography (CT) were performed, which showed arterial hyperenhancement with washout in delayed phase suggesting HCC, and a well-defined metastatic solid nodule, respectively. F-18 fluorodeoxyglucose positron emission tomography (PET)-CT exhibited multiple hypermetabolic lesions in the iliac bone, lumbar vertebrae, and femur. Because of the high burden of the intrahepatic tumor, transarterial radioembolization was initially performed; after 37 d, a combination therapy of Ate/Bev was administered. The patient visited the emergency department three days after Ate/Bev treatment complaining of dyspnea. He was diagnosed with severe pneumonitis based on CT. Despite administering oxygen via a high-flow nasal cannula, the P/F ratio was only 74; therefore, the patient was diagnosed with ARDS based on the overall examination results. Low tidal volume with high positive end-expiratory pressure, sedative agents combined with a neuromuscular blocker, and a systemic steroid were promptly applied to manage the ARDS. However, the patient did not recover from the hypoxia and expired 31 h after being admitted. CONCLUSION: Clinicians should be aware of severe pneumonitis due to the immune-related adverse events of this combination therapy, and patients should be closely monitored after therapy.